Use the getter instead of accessing the value directly

This fixes a valgrind issue with the dummy backend
and sdds the getter to the Bluez backernd.

Change-Id: I55c785e01bb428819b8ae9a936b761c3697ecb50
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>
Reviewed-by: Alex <alexander.blasche@digia.com>
Fix compiler warning

qbluetoothserviceinfo_bluez.cpp:87:5: warning: case value ‘33’ not in enumerated type ‘QVariant::Type’ [-Wswitch]
qbluetoothserviceinfo_bluez.cpp:81:5: warning: case value ‘34’ not in enumerated type ‘QVariant::Type’ [-Wswitch]
qbluetoothserviceinfo_bluez.cpp:67:5: warning: case value ‘36’ not in enumerated type ‘QVariant::Type’ [-Wswitch]
qbluetoothserviceinfo_bluez.cpp:60:5: warning: case value ‘37’ not in enumerated type ‘QVariant::Type’ [-Wswitch]
qbluetoothserviceinfo_bluez.cpp:57:5: warning: case value ‘43’ not in enumerated type ‘QVariant::Type’ [-Wswitch]

Change-Id: Ic5e792119e0676e09e1f4a3b07e5d3defa27c623
Reviewed-by: Michael Zanetti <michael.zanetti@canonical.com>
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Reviewed-by: Alex <alexander.blasche@digia.com>